How to cal Radcomobobox OnClientItemsRequesting only in enter key press

[Dhamodharan]

Hi All,

I am using RadComboBox binding with webservice. so every letter typing webservice method search in database. this is fine when small amount of data. but in my side it is large amount of data. so i do not want search every letter typing. i want this searching only enter key press instead of every letter. i want to set AutoPostBack="true" also. please help me with this one. this is important and performance issue for me. Please help ASAP.


Thanks in Advance,
Dhamodharan

[Boyan Dimitrov]

Hello Dhamodharan,

First you can use the RadComboBox MinFilterLenght that controls the minimum length of the typed text before the control initiates a request for new Items when EnableLoadOnDemand is True. If you set it to "3" the user have type at least 3 characters in the input field before the controls to initiates a request.

Second you can remove the EnableLoadOnDemand="True" and request the items manually. In this approach you can request the items when user opens the drop down and when clicks "Enter".
//markup code

<script type="text/javascript">
    function OnClientKeyPressing(sender, args) {
        var e = args.get_domEvent();
        if (e.which != 13) {
            sender.requestItems(sender.get_text());
           }
    }

    function OnClientDropDownOpened(sender, args) {
        sender.requestItems(sender.get_text());
    }
</script>

<telerik:RadComboBox ID="RadComboBox4" runat="server" Width="250px" Height="150px" AllowCustomText="true"
    EmptyMessage="Select a Company" ShowMoreResultsBox="true"
    EnableVirtualScrolling="true" Label="Page Methods:">
    <WebServiceSettings Method="GetCompanyNames" Path="Default.aspx" />
</telerik:RadComboBox>

Regards,
Boyan Dimitrov
Telerik

 

 

[Deepak]

How do i insert an emptry string as the first entry to a radcomboxbox where i have used SQLdatasource and enableautomaticondemandload = true enablevirtualscrolling = true . please help

[Deepak]

How do i insert an emptry string as the first entry to a radcomboxbox where i have used SQLdatasource and enableautomaticondemandload = true enablevirtualscrolling = true . please help

[Boyan Dimitrov]

Hello,

Please use the RadComboBox ItemsRequestes event handler as shown below:
//markup code

<telerik:RadComboBox ID="RadComboBox1" runat="server" Width="250" Height="150"
               EmptyMessage="Select a Company" DataSourceID="SqlDataSource1" DataTextField="CompanyName"
               DataValueField="CompanyName" EnableAutomaticLoadOnDemand="True" ItemsPerRequest="10" AppendDataBoundItems="true" OnItemsRequested="RadComboBox1_ItemsRequested"
               ShowMoreResultsBox="true" EnableVirtualScrolling="true" Label="Server-Side (Automatic):">
           </telerik:RadComboBox>

//code behind

protected void RadComboBox1_ItemsRequested(object sender, RadComboBoxItemsRequestedEventArgs e)
        {
            if (e.NumberOfItems <= 0)
            {
                (sender as RadComboBox).Items.Insert(0, new RadComboBoxItem() { Text="" });
            }
        }

Regards,
Boyan Dimitrov
Telerik

 

 

[Deepak]

Thanks but wot i did was that i had sqldatasource so i returned the dataset with first entry as null value so that way my condition is satisfied!!